Autism rates may be higher than thought
By Shari Roan, Los Angeles Times
May 8, 2011
In the first study to take a broad-population look at the prevalence of autism spectrum disorders — types of autism ranging from severe symptoms to the milder Asperger's syndrome [my note: ASD here includes autism, Asperger's and PDD-NOS] — researchers found a rate of 2.64% among South Korean children. That's 1 in 38 children, a rate far higher than the estimate of 1 in 110 children for the U.S. by the Centers for Disease Control and Prevention.
The five-year study, funded partly by Autism Speaks and led by Dr. Young-Shin Kim of the Yale Child Study Center, differed significantly in methodology from earlier autism-prevalence studies. This likely accounts for the dramatically different findings, Kim said.
Previous studies assessing population-wide autism rates typically focused on high-risk populations — such as classrooms of special education students. In contrast, the study conducted in South Korea assessed more than 55,000 children, ages 7 to 12, not only from special education classrooms and mental health service organizations but also regular schools.
Read full article here
Prevalence of Autism Spectrum Disorders in a Total Population Sample
Young Shin Kim, M.D., Ph.D., et al.
American Journal of Psychiatry
May 9, 2011
(Read study abstract or download the full text here)
Some interesting findings from this study:
"Two-thirds of ASD cases in the overall sample were in the mainstream school population, undiagnosed and untreated."
The prevalence rate in the US is 1 in 110. Presuming that this makes up just one-third of all ASD children (like in Korea) — the other 2/3 out there, uncounted, undiagnosed — that would mean the true rate of autism is closer to that of Korea: 1 in 37.
The population of this study is aged 7-12. Considering that autism rates have been steadily rising all around the world, Korea should be no exception, thus the rate among 0-7 year olds should be significantly higher than 1 in 38, bringing up the average as well. Keep in mind also that this study was conducted over a span of 5 years, so some of the 7-year-olds would now be 12 and some 12-year-olds are now 17. The children were born between 1993 and 1998, so it would be inaccurate to say that the rate of autism is now 1 in 38—it was already 1 in 38 in the 1990s! It would be helpful if the authors had broken down the prevalence rates by year of birth, so we can see if the rate of autism had increased over the years and by how much, instead of lumping everything together into one average. This is valuable data and they have not mined it as much as they could have. Unless they're just saving it for another paper.
So, what of the whole other younger generation that was born between 1998 and now? If you look at this chart, in 2006 (5 years ago, when this study began), the number of American children newly diagnosed at ages 0-4 is triple that of those whose autism was detected only when they were older (ages 5-9). This means that during the time the Korean study was conducted, had they included the 0-7 year olds, the rate of autism would definitely have been much higher than 1 in 38. Might the rate among under-sevens be triple as well—1 in 12—bringing the average up to 1 in 25?
If you are going to become a parent or already are a parent to a young child, it certainly behooves you to learn more about the causes of autism (and other now-epidemic neurological disorders like learning disabilities and ADHD) and avoid them.
• Healing and Preventing Autism
• Big Pharma Admits that Vaccines Cause Autism
• Pesticides and Autism